Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, video and the like, and deployments are likely to increase with introduction of new data oriented systems such as Long Term Evolution (LTE) systems. Wireless communications systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems and other orthogonal frequency division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals (also know as user equipments (UEs), or access terminals (ATs). Each terminal communicates with one or more base stations (also know as access points (APs), EnodeBs or eNBs) via transmissions on forward and reverse links. The forward link (also referred to as a downlink or DL) refers to the communication link from the base stations to the terminals, and the reverse link (also referred to as an uplink or UL) refers to the communication link from the terminals to the base stations. These communication links may be established via a single-in-single-out, single-in-multiple out, multiple-in-single-out or a multiple-in-multiple-out (MIMO) system.
Base station nodes, sometimes referred to as eNBs, may have different capabilities for deployment in a network. This includes transmission power classes, access restriction, and so forth. In one aspect, heterogeneous network characteristics create wireless coverage dead spots (e.g., Donut coverage hole). This may cause severe inter-cell interference requiring undesirable user equipment cell association. In general, heterogeneous network characteristics require deep penetration of physical channels, which may cause unwanted interference between nodes and equipment on the respective network.
As the number of mobile stations deployed increases, the need for proper bandwidth utilization becomes more important. Moreover, with the introduction of semiautonomous base stations for managing small cells, such as femtocells and picocells, in systems such as LTE, interference with existing base stations may become an increasing problem.